Injury is the principal health problem in America today and coordinated research in the treatment of injury has been generally lacking. The initial observations and treatments influence the ultimate outcome for the severely traumatized patients. This critical, early post-traumatic period is characterized by high plasma levels of regulatory hormones and also substrates liberated due to enhanced proteolysis, lipolysis, and gluconeogenesis. Timely recognition and better understanding of the mechanisms of the altered kinetics of the biological systems in trauma victims, especially in the elderly, is essential to provide optimal nutritional support with or without an adjuvant treatment. This series of clinical studies will attempt to identify the metabolic nutritional, biochemical, and other roles of the primary anabolic growth hormone (hGH) in trauma victims. This hypothesis that nitrogen economy and fat mobilization and utilization could be improved with definitive clinical advantages during the catabolic "flow" phase of major trauma by an adjuvant hGH therapy will be tested since trauma induces a temporary hGH deficiency. The investigators propose to systematically investigate, on a whole-body level, in severely traumatized adults with or without exogenous hGH administration (1) protein metabolism (turnover, synthesis and breakdown rates, nitrogen balance and daily excretions of polyamines and 3- methylhistidine), (2) metabolism (glycerol turnover, fat oxidation, and recycling), (3) lipid metabolism (glycerol turnover, fat oxidation and re-esterificaiton rates), (4) daily metabolic rate and fuel substrates oxidation rate (indirect calorimetry), (5) plasma levels of amino acids, hormones and substrates, (6) examine the course of changes in the majority of the above parameters during intravenous nutritional therapy for 6 to 8 days, and (7) correlate the interrelationships between the various parameters and propose mechanisms for the role of hGH in the early post-trauma period. This clinical investigation is an integrated, comprehensive study of protein, fat and carbohydrate metabolism in trauma.